1. Field of the Invention
The present invention generally relates to video signal reproducing apparatus and more particularly to a video signal reproducing apparatus for use with a VTR (video tape recorder).
2. Description of the Prior Art
When a magnetic tape on which a television program having a predetermined duration of time is recorded is played back by, for example, a VTR for broadcast station, in order to insert other information than the television program, for example, a commercial into the magnetic tape within the predetermined duration of time, such a method is proposed in which the video signal constituting the television program is skipped at every predetermined interval, for example, at every field. In order to skip the video information of, for example, one field, a so-called dynamic tracking system has been used so far in which the tape running speed relative to a rotary magnetic head is increased by, for example, about 1% relative to the tape running speed of the playback mode to thereby gradually displace the tracking position of a record track recorded obliquely on the magnetic tape by one field amount and when the tracking position is displaced by nearly one track, the rotary magnetic head jumps the succeeding track and reproduces the track adjacent to the skipped track.
By the way, in this case, when the rotary magnetic head jumps one track and moves to the track adjacent to the skipped track, a picture image signal of one field recorded on the track which is jumped by the rotary magnetic head is skipped from the reproduced video signal and lost. However, since the video signal thus reproduced is usually processed at the unit of the picture image signal of one frame formed of odd and even fields, the reproduced video signal having part of picture image information skipped has to undergo such signal processing that odd and even fields and a polarity of a chroma signal comply with a format of a standard television system.
As such prior art signal processing system, it is proposed that a picture image signal correcting circuit such as a line adding system is used to form a correcting picture image signal on the basis of picture image signals contained in adjacent two lines to thereby provide a picture image signal in which when a picture image information of one field is skipped, this skipped picture image information is interpolated.
However, according to this method, when the corrected picture image signal is matched in position so as to become continuous, there arises a problem that resolution of the resultant picture image is deteriorated. Further, in order to prevent the resolution of the picture image from being deteriorated, when the picture image signal is matched in position so as to maintain the resolution of the corrected picture image signal, there arises in turn a problem that the resultant picture image is moved in the up and down direction. In addition, as a second method for correcting the picture image, it is proposed that, of the reproduced video signal, a picture image signal as skipped field portion is jumped at frame unit such that odd and even fields of the reproduced video signal become coincident with those of a predetermined reference signal or that the skipped portion of the picture image signal is compensated for by repeatedly inserting the same data even-numbered times thereinto. However, this second method has a defect that the reproduced video signal, which is made discontinuous by the skipping of the picture image signal of one field, has further enlaged its discontinuous portion.